Anthrène des musées 
Museum beetle, Carpet beetle 
Gorgojo de museos 
Kabinettkäfer, Museumskäfer Anthrenus museorum have a polyphagous and necrophagous food diet. They prefer quiet places; they are fond of carpets, wardrobes, plinth areas, and they also live in rodents’, birds’ and fowl’s nests where they feed on dried animal fragments and debris. Adults have a very short lifetime of around 1 or 2 weeks. They do not cause any damage, whereas their larvae have a marked preference for insect collections and stuffed furry or feathered animals. They can survive in very, very dry environments. They are considered as the most harmful museum species worldwide, but in France other Anthrenus species (cf. A. verbasci fact-sheet) are found in museums and can be much more frequent. The species is commonly found in natural environments. Adults live on flowers and can be quite abundant (along with other Anthrenus species) on Apiaceae (Umbellifera) flowers where they feed on nectar and pollen. Adults are good fliers.
2 to 4 mm long
Round-shaped, head clearly visible, rather short pronotum
Eight-articled antennae, the last 2 articles form a club
Triangular-shaped thorax when seen from above.
Rather short legs that can fold back into their grooves on the ventral surface.
Almost black head.
Dark to black top with golden or whitish spots or stripes, more or less regularly distributed on thorax and elytra.
Ventral surface of a uniform light-grey colour.
4.5 mm long
Oval-shaped, like small, whitish grubs with long, erect black bristles on the top of their body and 3 bunches of converging hairs at their rear end.
Young larvae are a yellowish white, and they grow darker and darker as they get older.
It is almost identical to that of all Anthrenus species. In summer, females frequently get into houses to lay their eggs, provided that they can find food substrates for their larvae. They are strongly attracted by natural light; they can be seen on window panes and around windows, trying to reach the outside world. After fecundation, females lay between 20 and 200 eggs in carpets, woollen materials, small flooring cracks, birds’ nests…
Egg incubation requires between 11 and 15 days. Larval development length depends very much on temperature and on the nutrient richness of infested materials. In natural conditions, the full development cycle lasts about 12 months and there is one generation per year. In optimal thermo-hygrometric conditions and in heated places (30°C), cycle length is shorter and there can be two generations per year. Conversely, in unfavourable or extreme conditions, the whole development cycle can last up to 2 years, even more.
There are 5 to 6 consecutive larval molts on an average, but a maximum number of 29 has already been observed. At the end of their development, larvae turn into nymphs, which are rather short and a yellowish colour. Nymphosis lasts about 10 days at 24°C, slightly less if temperatures are higher (8 days at 30°C). Once the adult stage is reached, the imago lives in the larval remains for about a week before becoming active and taking flight.
As indicated by their name, museum beetles are very fond of museums where they seek insect collections, herbaria, stuffed animals, skins, furs, dessicated animal bodies, cotton goods, leather, wool, natural or artificial silk fibers, all kinds of paper goods, cereal, and diverse foodstuffs (especially when they contain starch).
The presence of Anthrenus museorum can be spotted above all from the damage they cause (material loss, holes,…), and from the presence of larval exoskeletons and of debris on materials.
Worldwide distribution, but more frequent in hot, humid regions.
